Magnetic induction for accelerated water evaporation in cold asphalt mixtures: large-scale evaluation and life cycle assessment

Abstract

Cold asphalt mixtures are considered a sustainable alternative to hot asphalt mixtures. However, their long curing times and lower durability remain major barriers to their implementation. The objective of this work was to evaluate the mechanical, technical, environmental and economic feasibility of reducing the curing time of cold asphalt mixtures with industrial by-products by means of magnetic induction technology. For this purpose, the mechanical performance of the experimental mixtures has been evaluated in a circular road simulator. In addition, a prototype of a full-scale magnetic induction machine has been designed. Afterwards, with the information obtained in the previous steps, an environmental and economic impact analysis has been realised. This cradle to grave study was conducted using a functional unit consisting of a 1000 m long road section. Four cases have been studied: two reference mixtures (one hot and one cold), and two experimental mixtures (one with virgin steel fibres and one with magnetic industrial by-product). Regarding the results, asphalt mixtures cured by magnetic induction show better mechanical performance than traditional cold asphalt mixtures, even though they still do not reach the performance level of hot mixtures. A construction prototype of a full-scale magnetic induction machine has been developed applying the current technology, which can be coupled to a traditional packer roller. This fast-curing method offers both environmental and economic advantages over traditional cold mixtures, although it still requires refinement to achieve feasibility comparable to hot asphalt mixtures. The economic and environmental sustainability of magnetic induction depends on the use of industrial by-products.